Weather Blog: Humidity hangs, rain chances linger

Thank you for stopping by the Weather Watch 12 blog! Southern Wisconsin will look and feel more like the tropics for the next two days. Dew points will stay in the uncomfortable range, and thunderstorms will have the potential produce soaking downpours. In today's blog we look at the timing of rain and how long the sticky fell hangs around.

For the rest of Monday a few spotty showers or isolated thunderstorms will be possible. Highs in the 80s will combine with dew points in the 60s to low 70s to produce a sultry feel to the air.

A stationary front will be draped across Wisconsin on Tuesday. The front will be the focal point for showers and thunderstorms to develop and move along. With ample moisture, and lift provided by the front, heavy rain is possible. The surface forecast map below is valid at 7am Tuesday.

Dew points will remain high on Tuesday with moisture pooling near the stationary front. Anytime dew points reach the 70s, that is considered tropical! The NAM dew point forecast map below is valid at 4pm Tuesday afternoon. This forecast is showing dew points in the low 70s near Milwaukee. Air conditioners are fans will be working overtime considering daytime highs will reach at least the mid 80s -- producing heat index values of 90 or higher.

On Tuesday, showers and thunderstorms are likely across central and southern Wisconsin. The question is where will the heaviest rain band set-up. Where that band moves will likely result in quick downpours dumping 1"-2"+ of rain. The highest likelihood for rain on Tuesday will be in the 2pm to midnight timeframe.

Let's check out two different computer models we use for forecasting. The NAM computer model forecast below is valid at 4pm Tuesday. This map shows darker green shades, or the potential for higher rain totals over southern Wisconsin. This forecast would likely bring a band of thunderstorms into southeast Wisconsin by late afternoon or evening.

Another model we use for forecasting is the GFS. The GFS develops a cluster of thunderstorms across central Wisconsin that would have the potential to dump heavy rain. The forecast map below shows the area of rain, and is valid at 7pm Tuesday.

The greatest impact from thunderstorms through Tuesday evening will be the potential for heavy rain and flash flooding. Other severe weather threats(high wind, hail, tornadoes) look to stay low during this period. Stay with Weather Watch 12 for updates on the timing and possible rainfall amounts.

By Wednesday afternoon dry weather takes hold as the humidity begins to drop. Thursday and Friday look like comfortable days across the entire state.

For the latest weather information watch WISN 12 News, and for updates throughout the day follow me on Twitter @jnelsonweather